Merge branch 'maint'
[paraslash.git] / afs.c
1 /*
2 * Copyright (C) 2007 Andre Noll <maan@tuebingen.mpg.de>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file afs.c Paraslash's audio file selector. */
8
9 #include <netinet/in.h>
10 #include <sys/socket.h>
11 #include <regex.h>
12 #include <signal.h>
13 #include <fnmatch.h>
14 #include <osl.h>
15 #include <lopsub.h>
16 #include <arpa/inet.h>
17 #include <sys/un.h>
18 #include <netdb.h>
19 #include <lopsub.h>
20
21 #include "server.lsg.h"
22 #include "server_cmd.lsg.h"
23 #include "para.h"
24 #include "error.h"
25 #include "crypt.h"
26 #include "string.h"
27 #include "afh.h"
28 #include "afs.h"
29 #include "server.h"
30 #include "net.h"
31 #include "ipc.h"
32 #include "list.h"
33 #include "sched.h"
34 #include "fd.h"
35 #include "signal.h"
36 #include "mood.h"
37 #include "sideband.h"
38 #include "command.h"
39
40 /** The osl tables used by afs. \sa blob.c. */
41 enum afs_table_num {
42 /** Contains audio file information. See aft.c. */
43 TBLNUM_AUDIO_FILES,
44 /** The table for the paraslash attributes. See attribute.c. */
45 TBLNUM_ATTRIBUTES,
46 /**
47 * Paraslash's scoring system is based on Gaussian normal
48 * distributions, and the relevant data is stored in the rbtrees of an
49 * osl table containing only volatile columns. See score.c for
50 * details.
51 */
52 TBLNUM_SCORES,
53 /**
54 * A standard blob table containing the mood definitions. For details
55 * see mood.c.
56 */
57 TBLNUM_MOODS,
58 /** A blob table containing lyrics on a per-song basis. */
59 TBLNUM_LYRICS,
60 /** Another blob table for images (for example album cover art). */
61 TBLNUM_IMAGES,
62 /** Yet another blob table for storing standard playlists. */
63 TBLNUM_PLAYLIST,
64 /** How many tables are in use? */
65 NUM_AFS_TABLES
66 };
67
68 static struct afs_table afs_tables[NUM_AFS_TABLES] = {
69 [TBLNUM_AUDIO_FILES] = {.init = aft_init, .name = "audio_files"},
70 [TBLNUM_ATTRIBUTES] = {.init = attribute_init, .name = "attributes"},
71 [TBLNUM_SCORES] = {.init = score_init, .name = "scores"},
72 [TBLNUM_MOODS] = {.init = moods_init, .name = "moods"},
73 [TBLNUM_LYRICS] = {.init = lyrics_init, .name = "lyrics"},
74 [TBLNUM_IMAGES] = {.init = images_init, .name = "images"},
75 [TBLNUM_PLAYLIST] = {.init = playlists_init, .name = "playlists"},
76 };
77
78 struct command_task {
79 /** The file descriptor for the local socket. */
80 int fd;
81 /**
82 * Value sent by the command handlers to identify themselves as
83 * children of the running para_server.
84 */
85 uint32_t cookie;
86 /** The associated task structure. */
87 struct task *task;
88 };
89
90 extern int mmd_mutex;
91 extern struct misc_meta_data *mmd;
92
93 static int server_socket;
94 static struct command_task command_task_struct;
95 static struct signal_task *signal_task;
96
97 static enum play_mode current_play_mode;
98 static char *current_mop; /* mode or playlist specifier. NULL means dummy mood */
99
100 /**
101 * A random number used to "authenticate" the connection.
102 *
103 * para_server picks this number by random before it forks the afs process. The
104 * command handlers know this number as well and write it to the afs socket,
105 * together with the id of the shared memory area which contains the payload of
106 * the afs command. A local process has to know this number to abuse the afs
107 * service provided by the local socket.
108 */
109 extern uint32_t afs_socket_cookie;
110
111 /**
112 * Struct to let command handlers execute a callback in afs context.
113 *
114 * Commands that need to change the state of afs can't change the relevant data
115 * structures directly because commands are executed in a child process, i.e.
116 * they get their own virtual address space.
117 *
118 * This structure is used by \p send_callback_request() (executed from handler
119 * context) in order to let the afs process call the specified function. An
120 * instance of that structure is written to a shared memory area together with
121 * the arguments to the callback function. The identifier of the shared memory
122 * area is written to the command socket.
123 *
124 * The afs process accepts connections on the command socket and reads the
125 * shared memory id, attaches the corresponding area, calls the given handler to
126 * perform the desired action and to optionally compute a result.
127 *
128 * The result and a \p callback_result structure is then written to another
129 * shared memory area. The identifier for that area is written to the handler's
130 * command socket, so that the handler process can read the id, attach the
131 * shared memory area and use the result.
132 *
133 * \sa struct callback_result.
134 */
135 struct callback_query {
136 /** The function to be called. */
137 afs_callback *handler;
138 /** The number of bytes of the query */
139 size_t query_size;
140 };
141
142 /**
143 * Structure embedded in the result of a callback.
144 *
145 * If the callback produced a result, an instance of that structure is embedded
146 * into the shared memory area holding the result, mainly to let the command
147 * handler know the size of the result.
148 *
149 * \sa struct callback_query.
150 */
151 struct callback_result {
152 /** The number of bytes of the result. */
153 size_t result_size;
154 /** The band designator (loglevel for the result). */
155 uint8_t band;
156 };
157
158 static int dispatch_result(int result_shmid, callback_result_handler *handler,
159 void *private_result_data)
160 {
161 struct osl_object result;
162 void *result_shm;
163 /* must attach r/w as result.data might get encrypted in-place. */
164 int ret2, ret = shm_attach(result_shmid, ATTACH_RW, &result_shm);
165 struct callback_result *cr = result_shm;
166
167 if (ret < 0) {
168 PARA_ERROR_LOG("attach failed: %s\n", para_strerror(-ret));
169 return ret;
170 }
171 result.size = cr->result_size;
172 result.data = result_shm + sizeof(*cr);
173 assert(handler);
174 ret = handler(&result, cr->band, private_result_data);
175 ret2 = shm_detach(result_shm);
176 if (ret2 < 0) {
177 PARA_ERROR_LOG("detach failed: %s\n", para_strerror(-ret2));
178 if (ret >= 0)
179 ret = ret2;
180 }
181 return ret;
182 }
183
184 /**
185 * Ask the afs process to call a given function.
186 *
187 * \param f The function to be called.
188 * \param query Pointer to arbitrary data for the callback.
189 * \param result_handler Called for each shm area sent by the callback.
190 * \param private_result_data Passed verbatim to \a result_handler.
191 *
192 * This function creates a socket for communication with the afs process and a
193 * shared memory area (sma) to which the buffer pointed to by \a query is
194 * copied. It then notifies the afs process that the callback function \a f
195 * should be executed by sending the shared memory identifier (shmid) to the
196 * socket.
197 *
198 * If the callback produces a result, it sends any number of shared memory
199 * identifiers back via the socket. For each such identifier received, \a
200 * result_handler is called. The contents of the sma identified by the received
201 * shmid are passed to that function as an osl object. The private_result_data
202 * pointer is passed as the second argument to \a result_handler.
203 *
204 * \return Number of shared memory areas dispatched on success, negative on errors.
205 *
206 * \sa send_option_arg_callback_request(), send_standard_callback_request().
207 */
208 int send_callback_request(afs_callback *f, struct osl_object *query,
209 callback_result_handler *result_handler,
210 void *private_result_data)
211 {
212 struct callback_query *cq;
213 int ret, fd = -1, query_shmid, result_shmid;
214 void *query_shm;
215 char buf[sizeof(afs_socket_cookie) + sizeof(int)];
216 size_t query_shm_size = sizeof(*cq);
217 int dispatch_error = 0, num_dispatched = 0;
218
219 if (query)
220 query_shm_size += query->size;
221 ret = shm_new(query_shm_size);
222 if (ret < 0)
223 return ret;
224 query_shmid = ret;
225 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
226 if (ret < 0)
227 goto out;
228 cq = query_shm;
229 cq->handler = f;
230 cq->query_size = query_shm_size - sizeof(*cq);
231
232 if (query)
233 memcpy(query_shm + sizeof(*cq), query->data, query->size);
234 ret = shm_detach(query_shm);
235 if (ret < 0)
236 goto out;
237
238 *(uint32_t *)buf = afs_socket_cookie;
239 *(int *)(buf + sizeof(afs_socket_cookie)) = query_shmid;
240
241 ret = connect_local_socket(OPT_STRING_VAL(AFS_SOCKET));
242 if (ret < 0)
243 goto out;
244 fd = ret;
245 ret = write_all(fd, buf, sizeof(buf));
246 if (ret < 0)
247 goto out;
248 /*
249 * Read all shmids from afs.
250 *
251 * Even if the dispatcher returns an error we _must_ continue to read
252 * shmids from fd so that we can destroy all shared memory areas that
253 * have been created for us by the afs process.
254 */
255 for (;;) {
256 ret = recv_bin_buffer(fd, buf, sizeof(int));
257 if (ret <= 0)
258 goto out;
259 assert(ret == sizeof(int));
260 ret = *(int *) buf;
261 assert(ret > 0);
262 result_shmid = ret;
263 ret = dispatch_result(result_shmid, result_handler,
264 private_result_data);
265 if (ret < 0 && dispatch_error >= 0)
266 dispatch_error = ret;
267 ret = shm_destroy(result_shmid);
268 if (ret < 0)
269 PARA_CRIT_LOG("destroy result failed: %s\n",
270 para_strerror(-ret));
271 num_dispatched++;
272 }
273 out:
274 if (shm_destroy(query_shmid) < 0)
275 PARA_CRIT_LOG("shm destroy error\n");
276 if (fd >= 0)
277 close(fd);
278 if (dispatch_error < 0)
279 return dispatch_error;
280 if (ret < 0)
281 return ret;
282 return num_dispatched;
283 }
284
285 /**
286 * Wrapper for send_callback_request() which passes a lopsub parse result.
287 *
288 * \param f The callback function.
289 * \param cmd Needed for (de-)serialization.
290 * \param lpr Must match cmd.
291 * \param private_result_data Passed to send_callback_request().
292 *
293 * This function serializes the parse result given by the lpr pointer into a
294 * buffer. The buffer is sent as the query to the afs process with the callback
295 * mechanism.
296 *
297 * \return The return value of the underlying call to send_callback_request().
298 */
299 int send_lls_callback_request(afs_callback *f,
300 const struct lls_command * const cmd,
301 struct lls_parse_result *lpr, void *private_result_data)
302 {
303 struct osl_object query;
304 char *buf = NULL;
305 int ret = lls_serialize_parse_result(lpr, cmd, &buf, &query.size);
306
307 assert(ret >= 0);
308 query.data = buf;
309 ret = send_callback_request(f, &query, afs_cb_result_handler,
310 private_result_data);
311 free(buf);
312 return ret;
313 }
314
315 static int action_if_pattern_matches(struct osl_row *row, void *data)
316 {
317 struct pattern_match_data *pmd = data;
318 struct osl_object name_obj;
319 const char *p, *name;
320 int i, ret;
321
322 ret = osl(osl_get_object(pmd->table, row, pmd->match_col_num,
323 &name_obj));
324 if (ret < 0)
325 return ret;
326 name = (char *)name_obj.data;
327 if ((!name || !*name) && (pmd->pm_flags & PM_SKIP_EMPTY_NAME))
328 return 1;
329 if (lls_num_inputs(pmd->lpr) == 0) {
330 if (pmd->pm_flags & PM_NO_PATTERN_MATCHES_EVERYTHING) {
331 pmd->num_matches++;
332 return pmd->action(pmd->table, row, name, pmd->data);
333 }
334 }
335 i = pmd->input_skip;
336 for (;;) {
337 if (i >= lls_num_inputs(pmd->lpr))
338 break;
339 p = lls_input(i, pmd->lpr);
340 ret = fnmatch(p, name, pmd->fnmatch_flags);
341 if (ret != FNM_NOMATCH) {
342 if (ret != 0)
343 return -E_FNMATCH;
344 ret = pmd->action(pmd->table, row, name, pmd->data);
345 if (ret >= 0)
346 pmd->num_matches++;
347 return ret;
348
349 }
350 i++;
351 }
352 return 1;
353 }
354
355 /**
356 * Execute the given function for each matching row.
357 *
358 * \param pmd Describes what to match and how.
359 *
360 * \return Standard.
361 */
362 int for_each_matching_row(struct pattern_match_data *pmd)
363 {
364 if (pmd->pm_flags & PM_REVERSE_LOOP)
365 return osl(osl_rbtree_loop_reverse(pmd->table, pmd->loop_col_num, pmd,
366 action_if_pattern_matches));
367 return osl(osl_rbtree_loop(pmd->table, pmd->loop_col_num, pmd,
368 action_if_pattern_matches));
369 }
370
371 /**
372 * Compare two osl objects of string type.
373 *
374 * \param obj1 Pointer to the first object.
375 * \param obj2 Pointer to the second object.
376 *
377 * In any case, only \p MIN(obj1->size, obj2->size) characters of each string
378 * are taken into account.
379 *
380 * \return It returns an integer less than, equal to, or greater than zero if
381 * \a obj1 is found, respectively, to be less than, to match, or be greater than
382 * obj2.
383 *
384 * \sa strcmp(3), strncmp(3), osl_compare_func.
385 */
386 int string_compare(const struct osl_object *obj1, const struct osl_object *obj2)
387 {
388 const char *str1 = (const char *)obj1->data;
389 const char *str2 = (const char *)obj2->data;
390 return strncmp(str1, str2, PARA_MIN(obj1->size, obj2->size));
391 }
392
393 static int pass_afd(int fd, char *buf, size_t size)
394 {
395 struct msghdr msg = {.msg_iov = NULL};
396 struct cmsghdr *cmsg;
397 char control[255] __a_aligned(8);
398 int ret;
399 struct iovec iov;
400
401 iov.iov_base = buf;
402 iov.iov_len = size;
403
404 msg.msg_iov = &iov;
405 msg.msg_iovlen = 1;
406
407 msg.msg_control = control;
408 msg.msg_controllen = sizeof(control);
409
410 cmsg = CMSG_FIRSTHDR(&msg);
411 cmsg->cmsg_level = SOL_SOCKET;
412 cmsg->cmsg_type = SCM_RIGHTS;
413 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
414 *(int *)CMSG_DATA(cmsg) = fd;
415
416 /* Sum of the length of all control messages in the buffer */
417 msg.msg_controllen = cmsg->cmsg_len;
418 PARA_DEBUG_LOG("passing %zu bytes and fd %d\n", size, fd);
419 ret = sendmsg(server_socket, &msg, 0);
420 if (ret < 0) {
421 ret = -ERRNO_TO_PARA_ERROR(errno);
422 return ret;
423 }
424 return 1;
425 }
426
427 /**
428 * Pass the fd of the next audio file to the server process.
429 *
430 * This stores all information for streaming the "best" audio file in a shared
431 * memory area. The id of that area and an open file descriptor for the next
432 * audio file are passed to the server process.
433 *
434 * \return Standard.
435 *
436 * \sa open_and_update_audio_file().
437 */
438 static int open_next_audio_file(void)
439 {
440 struct audio_file_data afd;
441 int ret, shmid;
442 char buf[8];
443
444 ret = open_and_update_audio_file(&afd);
445 if (ret < 0) {
446 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
447 goto no_admissible_files;
448 }
449 shmid = ret;
450 if (!write_ok(server_socket)) {
451 ret = -E_AFS_SOCKET;
452 goto destroy;
453 }
454 *(uint32_t *)buf = NEXT_AUDIO_FILE;
455 *(uint32_t *)(buf + 4) = (uint32_t)shmid;
456 ret = pass_afd(afd.fd, buf, 8);
457 close(afd.fd);
458 if (ret >= 0)
459 return ret;
460 destroy:
461 shm_destroy(shmid);
462 return ret;
463 no_admissible_files:
464 *(uint32_t *)buf = NO_ADMISSIBLE_FILES;
465 *(uint32_t *)(buf + 4) = (uint32_t)0;
466 return write_all(server_socket, buf, 8);
467 }
468
469 /* Never fails if arg == NULL */
470 static int activate_mood_or_playlist(const char *arg, int *num_admissible)
471 {
472 enum play_mode mode;
473 int ret;
474
475 if (!arg) {
476 ret = change_current_mood(NULL); /* always successful */
477 mode = PLAY_MODE_MOOD;
478 } else {
479 if (!strncmp(arg, "p/", 2)) {
480 ret = playlist_open(arg + 2);
481 mode = PLAY_MODE_PLAYLIST;
482 } else if (!strncmp(arg, "m/", 2)) {
483 ret = change_current_mood(arg + 2);
484 mode = PLAY_MODE_MOOD;
485 } else
486 return -E_AFS_SYNTAX;
487 if (ret < 0)
488 return ret;
489 }
490 if (num_admissible)
491 *num_admissible = ret;
492 current_play_mode = mode;
493 if (arg != current_mop) {
494 free(current_mop);
495 if (arg) {
496 current_mop = para_strdup(arg);
497 mutex_lock(mmd_mutex);
498 strncpy(mmd->afs_mode_string, arg,
499 sizeof(mmd->afs_mode_string));
500 mmd->afs_mode_string[sizeof(mmd->afs_mode_string) - 1] = '\0';
501 mutex_unlock(mmd_mutex);
502 } else {
503 mutex_lock(mmd_mutex);
504 strcpy(mmd->afs_mode_string, "dummy");
505 mutex_unlock(mmd_mutex);
506 current_mop = NULL;
507 }
508 }
509 return 1;
510 }
511
512 /**
513 * Result handler for sending data to the para_client process.
514 *
515 * \param result The data to be sent.
516 * \param band The band designator.
517 * \param private Pointer to the command context.
518 *
519 * \return The return value of the underlying call to \ref command.c::send_sb.
520 *
521 * \sa \ref callback_result_handler, \ref command.c::send_sb.
522 */
523 int afs_cb_result_handler(struct osl_object *result, uint8_t band,
524 void *private)
525 {
526 struct command_context *cc = private;
527
528 assert(cc);
529 switch (band) {
530 case SBD_OUTPUT:
531 case SBD_DEBUG_LOG:
532 case SBD_INFO_LOG:
533 case SBD_NOTICE_LOG:
534 case SBD_WARNING_LOG:
535 case SBD_ERROR_LOG:
536 case SBD_CRIT_LOG:
537 case SBD_EMERG_LOG:
538 assert(result->size > 0);
539 return send_sb(&cc->scc, result->data, result->size, band, true);
540 case SBD_AFS_CB_FAILURE:
541 return *(int *)(result->data);
542 default:
543 return -E_BAD_BAND;
544 }
545 }
546
547 static void flush_and_free_pb(struct para_buffer *pb)
548 {
549 int ret;
550 struct afs_max_size_handler_data *amshd = pb->private_data;
551
552 if (pb->buf && pb->size > 0) {
553 ret = pass_buffer_as_shm(amshd->fd, amshd->band, pb->buf,
554 pb->offset);
555 if (ret < 0)
556 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
557 }
558 free(pb->buf);
559 }
560
561 static int com_select_callback(struct afs_callback_arg *aca)
562 {
563 const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
564 const char *arg;
565 int num_admissible, ret;
566
567 ret = lls_deserialize_parse_result(aca->query.data, cmd, &aca->lpr);
568 assert(ret >= 0);
569 arg = lls_input(0, aca->lpr);
570 ret = clear_score_table();
571 if (ret < 0) {
572 para_printf(&aca->pbout, "could not clear score table\n");
573 goto free_lpr;
574 }
575 if (current_play_mode == PLAY_MODE_MOOD)
576 close_current_mood();
577 else
578 playlist_close();
579 ret = activate_mood_or_playlist(arg, &num_admissible);
580 if (ret >= 0)
581 goto out;
582 /* ignore subsequent errors (but log them) */
583 para_printf(&aca->pbout, "could not activate %s\n", arg);
584 if (current_mop) {
585 int ret2;
586 para_printf(&aca->pbout, "switching back to %s\n", current_mop);
587 ret2 = activate_mood_or_playlist(current_mop, &num_admissible);
588 if (ret2 >= 0)
589 goto out;
590 para_printf(&aca->pbout, "could not reactivate %s: %s\n",
591 current_mop, para_strerror(-ret2));
592 }
593 para_printf(&aca->pbout, "activating dummy mood\n");
594 activate_mood_or_playlist(NULL, &num_admissible);
595 out:
596 para_printf(&aca->pbout, "activated %s (%d admissible files)\n",
597 current_mop? current_mop : "dummy mood", num_admissible);
598 free_lpr:
599 lls_free_parse_result(aca->lpr, cmd);
600 return ret;
601 }
602
603 static int com_select(struct command_context *cc, struct lls_parse_result *lpr)
604 {
605 const struct lls_command *cmd = SERVER_CMD_CMD_PTR(SELECT);
606 char *errctx;
607 int ret = lls(lls_check_arg_count(lpr, 1, 1, &errctx));
608
609 if (ret < 0) {
610 send_errctx(cc, errctx);
611 return ret;
612 }
613 return send_lls_callback_request(com_select_callback, cmd, lpr, cc);
614 }
615 EXPORT_SERVER_CMD_HANDLER(select);
616
617 static void init_admissible_files(const char *arg)
618 {
619 if (activate_mood_or_playlist(arg, NULL) < 0)
620 activate_mood_or_playlist(NULL, NULL); /* always successful */
621 }
622
623 static int setup_command_socket_or_die(void)
624 {
625 int ret, socket_fd;
626 const char *socket_name = OPT_STRING_VAL(AFS_SOCKET);
627
628 unlink(socket_name);
629 ret = create_local_socket(socket_name);
630 if (ret < 0) {
631 PARA_EMERG_LOG("%s: %s\n", para_strerror(-ret), socket_name);
632 exit(EXIT_FAILURE);
633 }
634 socket_fd = ret;
635 PARA_INFO_LOG("listening on socket %s (fd %d)\n", socket_name,
636 socket_fd);
637 return socket_fd;
638 }
639
640 static void close_afs_tables(void)
641 {
642 int i;
643 PARA_NOTICE_LOG("closing afs_tables\n");
644 for (i = 0; i < NUM_AFS_TABLES; i++)
645 afs_tables[i].close();
646 }
647
648 static char *database_dir;
649
650 static void get_database_dir(void)
651 {
652 if (!database_dir) {
653 if (OPT_GIVEN(AFS_DATABASE_DIR))
654 database_dir = para_strdup(OPT_STRING_VAL(AFS_DATABASE_DIR));
655 else {
656 char *home = para_homedir();
657 database_dir = make_message(
658 "%s/.paraslash/afs_database-0.4", home);
659 free(home);
660 }
661 }
662 PARA_INFO_LOG("afs_database dir %s\n", database_dir);
663 }
664
665 static int make_database_dir(void)
666 {
667 int ret;
668
669 get_database_dir();
670 ret = para_mkdir(database_dir, 0777);
671 if (ret >= 0 || ret == -ERRNO_TO_PARA_ERROR(EEXIST))
672 return 1;
673 return ret;
674 }
675
676 static int open_afs_tables(void)
677 {
678 int i, ret;
679
680 get_database_dir();
681 PARA_NOTICE_LOG("opening %d osl tables in %s\n", NUM_AFS_TABLES,
682 database_dir);
683 for (i = 0; i < NUM_AFS_TABLES; i++) {
684 ret = afs_tables[i].open(database_dir);
685 if (ret >= 0)
686 continue;
687 PARA_ERROR_LOG("%s init: %s\n", afs_tables[i].name,
688 para_strerror(-ret));
689 break;
690 }
691 if (ret >= 0)
692 return ret;
693 while (i)
694 afs_tables[--i].close();
695 return ret;
696 }
697
698 static int afs_signal_post_select(struct sched *s, __a_unused void *context)
699 {
700 int signum, ret;
701
702 if (getppid() == 1) {
703 PARA_EMERG_LOG("para_server died\n");
704 goto shutdown;
705 }
706 signum = para_next_signal(&s->rfds);
707 if (signum == 0)
708 return 0;
709 if (signum == SIGHUP) {
710 close_afs_tables();
711 parse_config_or_die(1);
712 ret = open_afs_tables();
713 if (ret < 0)
714 return ret;
715 init_admissible_files(current_mop);
716 return 0;
717 }
718 PARA_EMERG_LOG("terminating on signal %d\n", signum);
719 shutdown:
720 task_notify_all(s, E_AFS_SIGNAL);
721 return -E_AFS_SIGNAL;
722 }
723
724 static void register_signal_task(struct sched *s)
725 {
726 para_sigaction(SIGPIPE, SIG_IGN);
727 signal_task = signal_init_or_die();
728 para_install_sighandler(SIGINT);
729 para_install_sighandler(SIGTERM);
730 para_install_sighandler(SIGHUP);
731
732 signal_task->task = task_register(&(struct task_info) {
733 .name = "signal",
734 .pre_select = signal_pre_select,
735 .post_select = afs_signal_post_select,
736 .context = signal_task,
737
738 }, s);
739 }
740
741 static struct list_head afs_client_list;
742
743 /** Describes one connected afs client. */
744 struct afs_client {
745 /** Position in the afs client list. */
746 struct list_head node;
747 /** The socket file descriptor for this client. */
748 int fd;
749 /** The time the client connected. */
750 struct timeval connect_time;
751 };
752
753 static void command_pre_select(struct sched *s, void *context)
754 {
755 struct command_task *ct = context;
756 struct afs_client *client;
757
758 para_fd_set(server_socket, &s->rfds, &s->max_fileno);
759 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
760 list_for_each_entry(client, &afs_client_list, node)
761 para_fd_set(client->fd, &s->rfds, &s->max_fileno);
762 }
763
764 /**
765 * Send data as shared memory to a file descriptor.
766 *
767 * \param fd File descriptor to send the shmid to.
768 * \param band The band designator for this data.
769 * \param buf The buffer holding the data to be sent.
770 * \param size The size of \a buf.
771 *
772 * This function creates a shared memory area large enough to hold
773 * the content given by \a buf and \a size and sends the identifier
774 * of this area to the file descriptor \a fd.
775 *
776 * It is called by the AFS max_size handler as well as directly by the AFS
777 * command callbacks to send command output to the command handlers.
778 *
779 * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
780 * and positive on success.
781 */
782 int pass_buffer_as_shm(int fd, uint8_t band, const char *buf, size_t size)
783 {
784 int ret, shmid;
785 void *shm;
786 struct callback_result *cr;
787
788 if (size == 0)
789 assert(band != SBD_OUTPUT);
790 ret = shm_new(size + sizeof(*cr));
791 if (ret < 0)
792 return ret;
793 shmid = ret;
794 ret = shm_attach(shmid, ATTACH_RW, &shm);
795 if (ret < 0)
796 goto err;
797 cr = shm;
798 cr->result_size = size;
799 cr->band = band;
800 if (size > 0)
801 memcpy(shm + sizeof(*cr), buf, size);
802 ret = shm_detach(shm);
803 if (ret < 0)
804 goto err;
805 ret = write_all(fd, (char *)&shmid, sizeof(int));
806 if (ret >= 0)
807 return ret;
808 err:
809 if (shm_destroy(shmid) < 0)
810 PARA_ERROR_LOG("destroy result failed\n");
811 return ret;
812 }
813
814 static int call_callback(int fd, int query_shmid)
815 {
816 void *query_shm;
817 struct callback_query *cq;
818 int ret, ret2;
819 struct afs_callback_arg aca = {.fd = fd};
820
821 ret = shm_attach(query_shmid, ATTACH_RW, &query_shm);
822 if (ret < 0)
823 return ret;
824 cq = query_shm;
825 aca.query.data = (char *)query_shm + sizeof(*cq);
826 aca.query.size = cq->query_size;
827 aca.pbout.max_size = shm_get_shmmax();
828 aca.pbout.max_size_handler = afs_max_size_handler;
829 aca.pbout.private_data = &(struct afs_max_size_handler_data) {
830 .fd = fd,
831 .band = SBD_OUTPUT
832 };
833 ret = cq->handler(&aca);
834 ret2 = shm_detach(query_shm);
835 if (ret2 < 0) {
836 if (ret < 0) /* ignore (but log) detach error */
837 PARA_ERROR_LOG("could not detach sma: %s\n",
838 para_strerror(-ret2));
839 else
840 ret = ret2;
841 }
842 flush_and_free_pb(&aca.pbout);
843 if (ret < 0) {
844 ret2 = pass_buffer_as_shm(fd, SBD_AFS_CB_FAILURE,
845 (const char *)&ret, sizeof(ret));
846 if (ret2 < 0)
847 PARA_ERROR_LOG("could not pass cb failure packet: %s\n",
848 para_strerror(-ret));
849 }
850 return ret;
851 }
852
853 static int execute_server_command(fd_set *rfds)
854 {
855 char buf[8];
856 size_t n;
857 int ret = read_nonblock(server_socket, buf, sizeof(buf) - 1, rfds, &n);
858
859 if (ret < 0 || n == 0)
860 return ret;
861 buf[n] = '\0';
862 if (strcmp(buf, "new"))
863 return -ERRNO_TO_PARA_ERROR(EINVAL);
864 return open_next_audio_file();
865 }
866
867 /* returns 0 if no data available, 1 else */
868 static int execute_afs_command(int fd, fd_set *rfds, uint32_t expected_cookie)
869 {
870 uint32_t cookie;
871 int query_shmid;
872 char buf[sizeof(cookie) + sizeof(query_shmid)];
873 size_t n;
874 int ret = read_nonblock(fd, buf, sizeof(buf), rfds, &n);
875
876 if (ret < 0)
877 goto err;
878 if (n == 0)
879 return 0;
880 if (n != sizeof(buf)) {
881 PARA_NOTICE_LOG("short read (%d bytes, expected %lu)\n",
882 ret, (long unsigned) sizeof(buf));
883 return 1;
884 }
885 cookie = *(uint32_t *)buf;
886 if (cookie != expected_cookie) {
887 PARA_NOTICE_LOG("received invalid cookie (got %u, expected %u)\n",
888 (unsigned)cookie, (unsigned)expected_cookie);
889 return 1;
890 }
891 query_shmid = *(int *)(buf + sizeof(cookie));
892 if (query_shmid < 0) {
893 PARA_WARNING_LOG("received invalid query shmid %d)\n",
894 query_shmid);
895 return 1;
896 }
897 ret = call_callback(fd, query_shmid);
898 if (ret >= 0)
899 return 1;
900 err:
901 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
902 return 1;
903 }
904
905 /** Shutdown connection if query has not arrived until this many seconds. */
906 #define AFS_CLIENT_TIMEOUT 3
907
908 static int command_post_select(struct sched *s, void *context)
909 {
910 struct command_task *ct = context;
911 struct sockaddr_un unix_addr;
912 struct afs_client *client, *tmp;
913 int fd, ret;
914
915 ret = task_get_notification(ct->task);
916 if (ret < 0)
917 return ret;
918 ret = execute_server_command(&s->rfds);
919 if (ret < 0) {
920 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
921 task_notify_all(s, -ret);
922 return ret;
923 }
924 /* Check the list of connected clients. */
925 list_for_each_entry_safe(client, tmp, &afs_client_list, node) {
926 ret = execute_afs_command(client->fd, &s->rfds, ct->cookie);
927 if (ret == 0) { /* prevent bogus connection flooding */
928 struct timeval diff;
929 tv_diff(now, &client->connect_time, &diff);
930 if (diff.tv_sec < AFS_CLIENT_TIMEOUT)
931 continue;
932 PARA_WARNING_LOG("connection timeout\n");
933 }
934 close(client->fd);
935 list_del(&client->node);
936 free(client);
937 }
938 /* Accept connections on the local socket. */
939 ret = para_accept(ct->fd, &s->rfds, &unix_addr, sizeof(unix_addr), &fd);
940 if (ret < 0)
941 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
942 if (ret <= 0)
943 return 0;
944 ret = mark_fd_nonblocking(fd);
945 if (ret < 0) {
946 PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
947 close(fd);
948 return 0;
949 }
950 client = para_malloc(sizeof(*client));
951 client->fd = fd;
952 client->connect_time = *now;
953 para_list_add(&client->node, &afs_client_list);
954 return 0;
955 }
956
957 static void register_command_task(uint32_t cookie, struct sched *s)
958 {
959 struct command_task *ct = &command_task_struct;
960 ct->fd = setup_command_socket_or_die();
961 ct->cookie = cookie;
962
963 ct->task = task_register(&(struct task_info) {
964 .name = "afs command",
965 .pre_select = command_pre_select,
966 .post_select = command_post_select,
967 .context = ct,
968 }, s);
969 }
970
971 /**
972 * Initialize the audio file selector process.
973 *
974 * \param cookie The value used for "authentication".
975 * \param socket_fd File descriptor used for communication with the server.
976 */
977 __noreturn void afs_init(uint32_t cookie, int socket_fd)
978 {
979 static struct sched s;
980 int i, ret;
981
982 register_signal_task(&s);
983 INIT_LIST_HEAD(&afs_client_list);
984 for (i = 0; i < NUM_AFS_TABLES; i++)
985 afs_tables[i].init(&afs_tables[i]);
986 ret = open_afs_tables();
987 if (ret < 0)
988 goto out;
989 server_socket = socket_fd;
990 ret = mark_fd_nonblocking(server_socket);
991 if (ret < 0)
992 goto out_close;
993 PARA_INFO_LOG("server_socket: %d, afs_socket_cookie: %u\n",
994 server_socket, (unsigned) cookie);
995 init_admissible_files(OPT_STRING_VAL(AFS_INITIAL_MODE));
996 register_command_task(cookie, &s);
997 s.default_timeout.tv_sec = 0;
998 s.default_timeout.tv_usec = 999 * 1000;
999 ret = write(socket_fd, "\0", 1);
1000 if (ret != 1) {
1001 if (ret == 0)
1002 errno = EINVAL;
1003 ret = -ERRNO_TO_PARA_ERROR(errno);
1004 goto out_close;
1005 }
1006 ret = schedule(&s);
1007 sched_shutdown(&s);
1008 out_close:
1009 close_afs_tables();
1010 out:
1011 if (ret < 0)
1012 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
1013 exit(EXIT_FAILURE);
1014 }
1015
1016 static int com_init_callback(struct afs_callback_arg *aca)
1017 {
1018 uint32_t table_mask = *(uint32_t *)aca->query.data;
1019 int i, ret;
1020
1021 close_afs_tables();
1022 for (i = 0; i < NUM_AFS_TABLES; i++) {
1023 struct afs_table *t = &afs_tables[i];
1024
1025 if (!(table_mask & (1 << i)))
1026 continue;
1027 if (!t->create)
1028 continue;
1029 ret = t->create(database_dir);
1030 if (ret < 0) {
1031 para_printf(&aca->pbout, "cannot create table %s\n",
1032 t->name);
1033 goto out;
1034 }
1035 para_printf(&aca->pbout, "successfully created %s table\n",
1036 t->name);
1037 }
1038 ret = open_afs_tables();
1039 if (ret < 0)
1040 para_printf(&aca->pbout, "cannot open afs tables\n");
1041 out:
1042 return ret;
1043 }
1044
1045 static int com_init(struct command_context *cc, struct lls_parse_result *lpr)
1046 {
1047 int i, j, ret;
1048 uint32_t table_mask = (1 << (NUM_AFS_TABLES + 1)) - 1;
1049 struct osl_object query = {.data = &table_mask,
1050 .size = sizeof(table_mask)};
1051 unsigned num_inputs = lls_num_inputs(lpr);
1052
1053 ret = make_database_dir();
1054 if (ret < 0)
1055 return ret;
1056 if (num_inputs > 0) {
1057 table_mask = 0;
1058 for (i = 0; i < num_inputs; i++) {
1059 for (j = 0; j < NUM_AFS_TABLES; j++) {
1060 struct afs_table *t = &afs_tables[j];
1061
1062 if (strcmp(lls_input(i, lpr), t->name))
1063 continue;
1064 table_mask |= (1 << j);
1065 break;
1066 }
1067 if (j == NUM_AFS_TABLES)
1068 return -E_BAD_TABLE_NAME;
1069 }
1070 }
1071 return send_callback_request(com_init_callback, &query,
1072 afs_cb_result_handler, cc);
1073 }
1074 EXPORT_SERVER_CMD_HANDLER(init);
1075
1076 static int com_check(struct command_context *cc, struct lls_parse_result *lpr)
1077 {
1078 const struct lls_opt_result *r_a = SERVER_CMD_OPT_RESULT(CHECK, AFT, lpr);
1079 const struct lls_opt_result *r_A = SERVER_CMD_OPT_RESULT(CHECK, ATTRIBUTE, lpr);
1080 const struct lls_opt_result *r_m = SERVER_CMD_OPT_RESULT(CHECK, MOOD, lpr);
1081 const struct lls_opt_result *r_p = SERVER_CMD_OPT_RESULT(CHECK, PLAYLIST, lpr);
1082 bool noopt = !lls_opt_given(r_a) && !lls_opt_given(r_A)
1083 && !lls_opt_given(r_m) && !lls_opt_given(r_p);
1084 int ret;
1085
1086 if (noopt || lls_opt_given(r_a)) {
1087 ret = send_callback_request(aft_check_callback, NULL,
1088 afs_cb_result_handler, cc);
1089 if (ret < 0)
1090 return ret;
1091 }
1092 if (noopt || lls_opt_given(r_A)) {
1093 ret = send_callback_request(attribute_check_callback, NULL,
1094 afs_cb_result_handler, cc);
1095 if (ret < 0)
1096 return ret;
1097 }
1098 if (noopt || lls_opt_given(r_p)) {
1099 ret = send_callback_request(playlist_check_callback,
1100 NULL, afs_cb_result_handler, cc);
1101 if (ret < 0)
1102 return ret;
1103 }
1104 if (noopt || lls_opt_given(r_m)) {
1105 ret = send_callback_request(mood_check_callback, NULL,
1106 afs_cb_result_handler, cc);
1107 if (ret < 0)
1108 return ret;
1109 }
1110 return 1;
1111 }
1112 EXPORT_SERVER_CMD_HANDLER(check);
1113
1114 /**
1115 * The afs event dispatcher.
1116 *
1117 * \param event Type of the event.
1118 * \param pb May be \p NULL.
1119 * \param data Type depends on \a event.
1120 *
1121 * This function calls each table event handler, passing \a pb and \a data
1122 * verbatim. It's up to the handlers to interpret the \a data pointer. If a
1123 * handler returns negative, the loop is aborted.
1124 *
1125 * \return The (negative) error code of the first handler that failed, or non-negative
1126 * if all handlers succeeded.
1127 */
1128 __must_check int afs_event(enum afs_events event, struct para_buffer *pb,
1129 void *data)
1130 {
1131 int i, ret;
1132
1133 for (i = 0; i < NUM_AFS_TABLES; i++) {
1134 struct afs_table *t = &afs_tables[i];
1135 if (!t->event_handler)
1136 continue;
1137 ret = t->event_handler(event, pb, data);
1138 if (ret < 0) {
1139 PARA_CRIT_LOG("table %s, event %u: %s\n", t->name,
1140 event, para_strerror(-ret));
1141 return ret;
1142 }
1143 }
1144 return 1;
1145 }
1146
1147 /**
1148 * Dummy event handler for the images table.
1149 *
1150 * \param event Unused.
1151 * \param pb Unused.
1152 * \param data Unused.
1153 *
1154 * \return The images table does not honor events, so this handler always
1155 * returns success.
1156 */
1157 __a_const int images_event_handler(__a_unused enum afs_events event,
1158 __a_unused struct para_buffer *pb, __a_unused void *data)
1159 {
1160 return 1;
1161 }
1162
1163 /**
1164 * Dummy event handler for the lyrics table.
1165 *
1166 * \param event Unused.
1167 * \param pb Unused.
1168 * \param data Unused.
1169 *
1170 * \return The lyrics table does not honor events, so this handler always
1171 * returns success.
1172 */
1173 __a_const int lyrics_event_handler(__a_unused enum afs_events event,
1174 __a_unused struct para_buffer *pb, __a_unused void *data)
1175 {
1176 return 1;
1177 }